When exercise triggers your asthma

If you’re looking after your asthma well, you should be able to enjoy exercise and all its benefits without it triggering your asthma symptoms.

Health advice > Asthma triggers

Know why exercise can be a trigger, the signs to look out for, how to tell normal exercise symptoms from asthma symptoms, and how good asthma control can help you avoid asthma symptoms when you exercise.

On this page:

Why exercise can be a trigger

Breathing through the nose warms up the air we breathe in. But when we exercise, particularly exercise that is more strenuous like running, we usually breathe through the mouth instead of the nose. This means we’re breathing in air that’s colder and drier than normal.

If you have asthma, breathing in this cold, dry air causes your airways to tighten and get narrower. This can trigger your asthma symptoms like coughing, wheezing, and breathlessness.

You may come across other triggers when you exercise too, like pollution or pollen if you exercise outside, or dust if you exercise indoors. Chlorine in swimming pools can also trigger symptoms for some people.

You’re more likely to get asthma symptoms when you exercise if:

‘Exercise-induced’ asthma 

Rarely, someone not diagnosed with asthma might get asthma-like symptoms from exercising.

This is often called ‘exercise-induced asthma’, but a better term is ‘exercise-induced bronchoconstriction’ (EIB) because it is not caused by having asthma. However, it’s important to be assessed for asthma if you have symptoms of EIB.

Bronchoconstriction is when the airways get tighter and narrower as a result of strenuous exercise, particularly if someone is also breathing in cold air.

Elite athletes, particularly athletes that exercise in cold air like cross-country skiers, are more likely to have EIB.

Find out more about exercise-induced asthma/bronchoconstriction.

Signs that exercise is triggering your asthma symptoms

Whether you’re out for a run, playing team sports, or cycling to work, don’t ignore important signs like:

  • needing to use your reliever inhaler
  • stopping to catch your breath.

Exercise or allergy? 

  • If exercise is the trigger, you might notice symptoms coming on after you’ve exercised. You may need about 30-60 minutes to recover.
  • If an allergy is the trigger, (for example pollen, or dust), you might notice symptoms during exercise.

Normal exercise symptoms or asthma symptoms?

It’s normal to breathe faster or more deeply when we do any strenuous exercise, whether that’s Zumba or running up the stairs.

So how can you tell if you’re breathless because of the exertion or because your asthma symptoms are flaring up?

Look out for these asthma signs:

  • Feeling very short of breath, or like you can’t breathe enough air in
  • Coughing
  • Wheezing
  • A tight feeling in your chest.

If you have any of these symptoms when you exercise, see your GP to review your asthma.


Always carry your reliever inhaler

Always have your blue reliever inhaler with you so you can quickly deal with asthma symptoms or an asthma attack. Call 999 if your reliever inhaler is not helping.

How to lower your risk of asthma symptoms when exercising

If exercise triggers your asthma symptoms, it’s usually a sign that your asthma is not as well controlled as it could be. You can lower your risk of symptoms when you exercise by:

  • Using your preventer inhaler every day as prescribed
  • Seeing your GP or asthma nurse to review your asthma.

Get more advice on exercising safely and motivation to stay active

Using your preventer inhaler every day

Using your preventer inhaler every day can lower your risk of asthma symptoms triggered by exercise.

Your preventer inhaler works in the background to prevent your airways from getting too inflamed. This means your airways are less likely to react when you exercise. 

A good preventer inhaler routine can also lower your risk of symptoms triggered by pollen, pollution, or dust when you’re exercising. 

Seeing your GP or asthma nurse

Your GP or asthma nurse can support you to manage your asthma well so you can feel confident about exercising.  

They can check your inhaler technique and update your asthma action plan. They may test your peak flow or suggest different asthma medicines.

A few people whose asthma is triggered by exercise may be told to use their reliever inhaler before they start exercising. For some people, this can help stop symptoms from coming on.

Find out more about the benefits of staying active

As long as your asthma is well managed, you should still be able to enjoy exercise and all the benefits of being active.

Find out more about exercising safely with asthma and which activities might be best for you to try, from gardening to adventure sports.


Last updated February 2021

Next review due February 2024

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